Field of the Invention
The present invention relates generally to locking mechanisms and methods of locking drawers and cabinet doors, and more particularly to an improved locking mechanism and a method of installing such a locking mechanism to prevent a drawer or a cabinet door from being fully opened when locked, the locking mechanism being concealed from view until the drawer or cabinet door is opened slightly and effectively preventing the drawer or cabinet door from being fully opened until the locking mechanism is unlocked.
A wide variety of locking mechanisms for use with drawers or cabinet doors have been developed for use in preventing access to the contents of such drawers or cabinets. There have been two prevalent reasons for using such locking mechanisms: first, to secure the contents of a drawer or cabinet; and second, to prevent children from gaining access to dangerous or fragile contents of a drawer or cabinet.
While the first reason has always required the use of a positive locking mechanism, the second reason has resulted in a wide variety of mechanical latches which are designed to be opened by adults while preventing at least small children from opening them. Unfortunately, all too often, small children are able to easily open such mechanical latches, while adults are able to open them only with considerable difficulty. Accordingly, the present invention is concerned with a locking mechanism rather than with a latching mechanism.
As might well be expected, the art is replete with examples of such locking mechanisms. Four examples of locking mechanisms illustrated in the art will be mentioned briefly. The first, which is illustrated in U.S. Pat. No. 2,094,895, to Karpenske et al., shows a locking mechanism for securing drawers in a desk. A key lock contained in the top center drawer of the desk actuates a mechanism which locks all of the drawers in the desk. In a further aspect, Karpenske et al. teach the use of the locking mechanism to secure handles in a recessed position within the drawers until the drawers are unlocked, at which time the handles are released so that they may be used to pull the drawers out.
While the Karpenske et al. reference is quite clever in its construction, it has the considerable drawback that it requires a highly complex mechanism which must be built into both the frame of the desk and the drawers. This mechanism is simply not readily adaptable for use with either previously installed drawers or with cabinet doors.
A second type of locking mechanism for use with drawers is illustrated in U.S. Pat. No. 3,909,090, to Breckner et al. The Breckner et al. reference teaches an interlocking drawer locking mechanism for use with a multi-drawer filing cabinet to prevent more than one drawer from being opened at a time. This mechanism is useful to prevent the weight of the contents of the drawers from tipping the filing cabinet over if more than one drawer is opened at the same time.
Unfortunately, like the Karpenske et al. reference discussed above, the Breckner et al. reference requires a mechanism that is built in and is not readily adaptable to installation at a later time. In addition, it actually does not lock any of the drawers in a filing cabinet; rather, Breckner et al. allows all of the drawers to be opened, but just one at a time.
A third type of locking mechanism is illustrated by U.S. Pat. No. 2,886,392, to Stegmaler. The Stegmaler reference also shows a filing cabinet locking system, with a combination lock mounted on one drawer being used to lock all of the drawers in the filing cabinet. When the combination lock is unlocked, the drawer on which the combination lock is mounted may be slid partly out to unlock all of the other drawers. Just like the other references previously mentioned, the Stegmaler reference is built into the filing cabinet and is not particularly adaptable for use with existing drawers or cabinet doors.
Finally, one additional reference will be mentioned by way of example to illustrate the complexity of much of the previously known art. U.S. Pat. No. 4,460,222, to Larking, teaches a drawer apparatus with a relatively simple locking mechanism. The Larking device is a drawer for use in banks and similar secure applications, with a simple mechanism used to prevent it from being opened from the outside once it has been locked from the inside. Even the simple mechanism disclosed in Larking must be built in, and is simply not adaptable for use on unsecured drawers without a great deal of difficulty.
It is accordingly the primary objective of the present invention that it provide a locking mechanism which may be installed to releasably secure a single drawer or a cabinet door. It is a further principal objective of the present invention that the locking mechanism be completely invisible until and unless the drawer or the cabinet door is partially opened. As such, it is a related objective of the present invention that it allow the drawer or the cabinet door on which it is installed to be opened sufficiently to allow access to the locking mechanism so that it may be unlocked, but that it effectively deny access to the contents of the drawer or the cabinet unless and until it is unlocked.
It is a further objective of the hidden locking mechanism of the present invention that it be quick and easy to lock and unlock. It is yet a further objective of the hidden locking mechanism of the present invention that it be sufficiently flexible to allow its use on a variety of different size and configuration drawers and cabinet doors without requiring a wide variety of different configurations to be provided, and that it be installable using only simple hand tools. It is a still further objective of the hidden locking mechanism of the present invention that it be configurable as either a key lock or a combination lock, and that it categorically prevent children from unlocking the locking mechanism unless they have the key or the combination.
The hidden locking mechanism of the present invention must be of a construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to enhance the market appeal of the hidden locking mechanism of the present invention, it should also be of inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the hidden locking mechanism of the present invention be achieved without incurring any substantial relative disadvantage.